摘要:
An MTJ in an MRAM array or TMR read head is disclosed in which a capping layer has a bilayer configuration with a non-magnetic NiFeX inner layer on a NiFe free layer and a Ta layer on the NiFeX layer to improve dR/R and minimize magnetostriction. Optionally, a trilayer configuration may be employed where the Ta layer is sandwiched between an inner NiFeX layer and an outer Ru layer. The X component in NiFeX is preferably an element having an oxidation potential greater than Ni or Fe such as Mg, Hf, Zr, Nb, or Ta. NiFeX is preferably formed by co-sputtering a NiFe target with an X target at a forward power of about 200 W and 50 W, respectively. In an MRAM structure, the Mg content in NiFeMg may be increased to >50 atomic % to improve the gettering power of removing oxygen from the free layer.
摘要:
An MTJ in an MRAM array or TMR read head is disclosed in which a capping layer has a bilayer configuration with a non-magnetic NiFeX inner layer on a NiFe free layer and a Ta layer on the NiFeX layer to improve dR/R and minimize magnetostriction. Optionally, a trilayer configuration may be employed where the Ta layer is sandwiched between an inner NiFeX layer and an outer Ru layer. The X component in NiFeX is preferably an element having an oxidation potential greater than Ni or Fe such as Mg, Hf, Zr, Nb, or Ta. NiFeX is preferably formed by co-sputtering a NiFe target with an X target at a forward power of about 200 W and 50 W, respectively. In an MRAM structure, the Mg content in NiFeMg may be increased to >50 atomic % to improve the gettering power of removing oxygen from the free layer.
摘要:
A multi-layered bottom electrode for an MTJ device on a silicon nitride substrate is described. It comprises a bilayer of alpha tantalum on ruthenium which in turn lies on a nickel chrome layer over a second tantalum layer.
摘要:
Formation of a bottom electrode for an MTJ device on a silicon nitride substrate is facilitated by including a protective coating that is partly consumed during etching of the alpha tantalum portion of said bottom electrode. Adhesion to SiN is enhanced by using a TaN/NiCr bilayer as “glue”.
摘要:
A MTJ for a spintronic device is disclosed and includes a thin composite seed layer made of at least Ta and a metal layer having fcc(111) or hcp(001) texture as in Ta/Ti/Cu to enhance perpendicular magnetic anisotropy (PMA) in an overlying laminated layer with a (CoFe/Ni)x, (Co/NiFe)x, (Co/NiCo)x, (CoFe/NiFe)x, or (CoFe/NiCo)x composition where x is from 5 to 30. In one embodiment, a CPP-TMR spin valve has one or both of a laminated free layer and laminated reference layer with the aforementioned compositions. The MTJ includes an interfacial layer made of CoFeB, CoFeB/CoFe, or CoFe/CoFeB between each laminated structure and the tunnel barrier. The laminated layers are deposited by a low power and high Ar pressure process to avoid damaging interfaces between adjoining layers. Annealing occurs at 220° C. to 400° C. A laminated layer with high PMA may also be included in one or more layers of a spin transfer oscillator.
摘要:
An MRAM is disclosed that has a MTJ comprised of a ferromagnetic layer with a magnetization direction along a first axis, a super-paramagnetic (SP) free layer, and an insulating layer formed therebetween. The SP free layer has a remnant magnetization that is substantially zero in the absence of an external field, and in which magnetization is roughly proportional to an external field until reaching a saturation value. In one embodiment, a separate storage layer is formed above, below, or adjacent to the MTJ and has uniaxial anisotropy with a magnetization direction along its easy axis which parallels the first axis. In a second embodiment, the storage layer is formed on a non-magnetic conducting spacer layer within the MTJ and is patterned simultaneously with the MTJ. The SP free layer may be multiple layers or laminated layers of CoFeB. The storage layer may have a SyAP configuration and a laminated structure.
摘要:
An MRAM is disclosed that has a MTJ comprised of a ferromagnetic layer with a magnetization direction along a first axis, a super-paramagnetic (SP) free layer, and an insulating layer formed therebetween. The SP free layer has a remnant magnetization that is substantially zero in the absence of an external field, and in which magnetization is roughly proportional to an external field until reaching a saturation value. In one embodiment, a separate storage layer is formed above, below, or adjacent to the MTJ and has uniaxial anisotropy with a magnetization direction along its easy axis which parallels the first axis. In a second embodiment, the storage layer is formed on a non-magnetic conducting spacer layer within the MTJ and is patterned simultaneously with the MTJ. The SP free layer may be multiple layers or laminated layers of CoFeB. The storage layer may have a SyAP configuration and a laminated structure.
摘要:
An MRAM is disclosed that has a MTJ comprised of a ferromagnetic layer with a magnetization direction along a first axis, a super-paramagnetic (SP) free layer, and an insulating layer formed therebetween. The SP free layer has a remnant magnetization that is substantially zero in the absence of an external field, and in which magnetization is roughly proportional to an external field until reaching a saturation value. In one embodiment, a separate storage layer is formed above, below, or adjacent to the MTJ and has uniaxial anisotropy with a magnetization direction along its easy axis which parallels the first axis. In a second embodiment, the storage layer is formed on a non-magnetic conducting spacer layer within the MTJ and is patterned simultaneously with the MTJ. The SP free layer may be multiple layers or laminated layers of CoFeB. The storage layer may have a SyAP configuration and a laminated structure.